Multi-piece, in particular two-piece, pistons for internal combustion engines are known in the prior art. DE 10 2013 218 764 A1, for example, discloses a two-piece piston, which is built up from a piston top part and a piston bottom part. With the two piston parts in the joined state, the configured parting surface gives rise to a joint, at least in the critical area of the piston rings or the piston skirt and possibly also in the particularly critical area of the piston head (combustion chamber recess, piston crown). Here multi-piece pistons according to the prior art are basically divided into piston top part and piston bottom part, the piston top part usually comprising the piston ring portion and the piston bottom part comprising the piston skirt. A joint or a gap therefore always results in an area of the outermost circumferential surface of the piston; for example between the piston ring portion and the piston skirt, or in the area of the piston rings. This joint or gap consequently lies in the area where the piston interacts with the cylinder wall of an internal combustion engine and close to the combustion chamber, in a thermally and mechanically highly stressed area of the piston. If a joint is provided in the piston head, this joint lies in an area subjected to particularly high thermal and mechanical stresses.
Proceeding from the prior art, the object of the present invention is to provide a multi-piece piston which affords an improved parting surface geometry.
These and other objects, which are yet to be stated in a reading of the following description or which may be clear to the person skilled in the art, are achieved by the subject matter of the independent claim. The dependent claims develop the central idea of the present invention in a particularly advantageous manner.